 Background, patients who are hospitalized with acute coronary syndrome, ACS, or heart failure, HF, are frequently readmitted. This is the first randomized controlled trial of a mobile health intervention that combines telemonitoring and education for inpatients with ACS or HF to prevent readmission. Objective, the aim of this study is to investigate the feasibility, efficacy, and cost-effectiveness of a smartphone app-based. This article was authored by Praveen Indaratna, Uzil Bisvas, James McFay, and others.